Tag: Genetics

Secrets of M458

Various Y chromosome haplogroups correlate with continental boundaries, except for one – R1a. The R1a is spread over a huge area from South Asia to Central East Europe to South Siberia. It also covers a large number of language groups like Slavic, Indo-Iranian, Finno-Ugric, Dravidian and Turkic. This combination means only one thing: the R1a can give us clues about the Indo-European homeland. But the R1a is not helpful in finding the Indo-European homeland because we still don’t know where it originated. Some say it originated in North India; others, Eastern Europe near Ukraine[2].
Since R1a is spread over a vast region, it often associated with one version of AMT: the Kurgan hypothesis. According to the theory which argues for the homeland in the Caucasus, Indo-Europeans mounted their horses and imposed their culture in Old Europe. These violent people changed history in the fifth and fourth millennium BCE and eventually arrived in India[1].
This theory had its own share of criticism. For example, just because the horse was domesticated in steppes does not mean that they fought on horsebacks; there is no linguistic evidence for it. Also when linguists compared the flora, fauna and technology of Kurgan culture with the reconstructions in PIE, there were discrepancies. Does the reconstructed word for horse mean a domesticated horse or a wild one? We don’t know[1].
Now a new R1a marker named the M458 has been found which has been helpful, not in finding the origins of the Indo-European homeland, but where it could not have come from. The M458 originated between 10, 000 to 7000 years back in Eastern Europe and is related to a number of Central and East European farming cultures. This marker, which is from the Kurgan area, does not extend eastward beyond the Ural Mountains and southward beyond Turkey[2].
Since the origin and spread of this marker coincides with the transformation of foragers to farmers, could those Neolithic farmers have spread from Eastern Europe to India like in the Anatolian hypothesis? An alternative to the Kurgan hypothesis, the Anatolian hypothesis states that Indo-Europeans were not aggressive people, but sedentery agriculturalists who spread along with the spread of farming techniques. Here the date is not the fourth of fifth millennium BCE, but the seventh[1].
The new paper says that there is no trace of the M458 marker, which peaks among Finno-Ugric and Slavic speakers, in India. This means that male genes did not flow from East Europe to India since 7000 – 5000 years back or that Indo-Europeans did not come from the following locations in Europe or these[2].

References:

  1. Edwin Bryant, The Quest for the Origins of Vedic Culture: The Indo-Aryan Migration Debate (Oxford University Press, USA, 2004).
  2. Peter A Underhill et al., “Separating the post-Glacial coancestry of European and Asian Y chromosomes within haplogroup R1a,” Eur J Hum Genet (November 4, 2009), http://dx.doi.org/10.1038/ejhg.2009.194.

The Aryan-Dravidian divide myth

A new paper published in Nature reveals that Indians are descendents of two genetically divergent ancient populations. One of the groups, Ancient North Indians (ANI), is closer to Middle Easterners, Central Asians, and Europeans and the other, Ancient South Indians (ASI), is quite distinct from the ANI. At some unknown point in time these two groups, which don’t exist now, mixed and the rest was Indian history[1].
Before getting into the findings, it is important to to mention certain notions that prevalent today. The most prominent among them is the discredited Aryan invasion theory which has morphed into the Aryan migration/trickle-down theory. According to this theory, around the middle of the fourth millennium an “unknown disturbance” triggered a cluster of Indo-Europeans tribes in Central Asia on a trip across the continent. This group of nomadic people wandered around looking for a place where there is sun, water and grass for their cattle. They reached India, around 1500 – 1200 BCE and during the journey “forgot” about their wanderings through Central Asia, Iran and Afghanistan[2]. In the simplified version, these Indo-European speakers mixed with the native Dravidians, but 3500 years later, those divisions are still exploited by politicians.
The study finds that there are differences between caste groups and tribals and between Indo-European speakers and Dravidian speaking population, but despite those differences, they are closer to each other than to outsiders like Europeans or East Asians. This is because, after the founder event, only few external genes mixed into the Indian gene pool. Thus the Dravidian Karunanidhi and the Indo-European speaking Mallika Sherawat are genetically not much different or in simple terms: there is no Aryan-Dravidian divide.
While no divide exists, what exists is a gradient with different groups having different levels of ANI in them, including Dravidian speakers and tribals. The level of ANI varies from 39 – 71% with higher values in upper castes and Indo-European speakers.
Thus if mainland tribals and Dravidian speakers are not “pure” ASI then who are? Since ANI is closer to Middle Easterners, Central Asians, and Europeans, those without this component can be considered to be pure descendents of the ancestral population which gave rise to ASI. The study found that there indeed is a group like that: the Onge people, who live in the Andamans and as per the last census there were 95 of them. The remaining one billion and change have some “foreign” gene in them, including K Veeramani.
When did the ANI originate? Other than the fact that ANI is genetically closer to Middle Easterners, Central Asians, and Europeans, what else do we know about them? Also when did the ANI-ASI mixture happen?

In paper the authors don’t give a time frame for the origin of ANI or the mixture of ANI and ASI, but speculate that the ancestral population of the ANI could have spoken proto-Indo-European. This is a bit controversial since it synchronizes events with the arrival of Aryans. But in a later press conference they pushed back on the time.

“The initial settlement took place 65,000 years ago in the Andamans and in ancient south India around the same time, which led to population growth in this part,” said Thangarajan. He added, “At a later stage, 40,000 years ago, the ancient north Indians emerged which in turn led to rise in numbers here. But at some point of time, the ancient north and the ancient south mixed, giving birth to a different set of population. And that is the population which exists now and there is a genetic relationship between the population within India.” [Aryan-Dravidian divide a myth: Study]

This agrees with the journey of man over the past 160,000 years. But if ANI emerged 40,000 years back, they would not be speaking proto-Indo-European, but would be singing Frits Staal’s bird songs. Genetic evidence supports the fact that common ancestors of Indians and Europeans lived more than 40,000 years ago.

“We found an extensive deep late Pleistocene genetic link between contemporary Europeans and Indians, provided by the mtDNA haplogroup U, which encompasses roughly a fifth of mtDNA lineages of both populations. Our estimate for this split [between Europeans and Indians] is close to the suggested time for the peopling of Asia and the first expansion of anatomically modern humans in Eurasia and likely pre-dates their spread to Europe.” [Genetics and the Aryan Debate]

and according to another study.

“The supposed Aryan invasion of India 3,000-4,000 years before present therefore did not make a major splash in the Indian gene pool. This is especially counter-indicated by the presence of equal, though very low, frequencies of the western Eurasian mtDNA types in both southern and northern India. Thus, the ‘caucasoid’ features of south Asians may best be considered ‘pre-caucasoid’ – that is, part of a diverse north or north-east African gene pool that yielded separate origins for western Eurasian and southern Asian populations over 50,000 years ago.” [Genetics and the Aryan Debate]

Thus Ancient North Indians emerged not during the Aryan migration but 40 millennia before that. Hence it would be hard pressed to imagine that they would wait till Max Muller and various colonials gave the go to mix with the ASI.
In the paper, the authors write, “A priority for future work should be to estimate a date for the mixture, which may be possible by studying the length of stretches of ANI ancestry in Indian samples.” That definitely should tell us what happened from the rise of ANI to present.
References:

  1. Reconstructing Indian population history by David Reich et. al.
  2. Gem in the Lotus by Abraham Eraly
  3. The peopling of India, by Michel Danino,Pragati,June 2009

See Also:

  1. Indians as hybrids (a.k.a Aryan invasion in the house!)
  2. SNPtastic India